Immunologically active polysaccharides from Centrosema pubescens.

Two polysaccharides with mean M(r)s of 2.0 x 10(6) and 3.75 x 10(5), were isolated from powdered seeds of Centrosema pubescens by fractionation on Sephacryl S-300 HR. Chemical and spectroscopic studies indicated that they have a backbone chain composed of beta-(1-->4)-linked D-galactopyranose residues having branches composed of alpha-(1-->5)-linked L-arabinofuranose residues at position 6 of D-galactose of the backbone chain. The polysaccharides showed reticuloendothelial system-potentiating activity in a carbon clearance test.